
from django.core.paginator import Paginator, EmptyPage, PageNotAnInteger
from django.shortcuts import render, get_object_or_404
from django.core.mail import send_mail
from .models import Post 
 
from django.shortcuts import render, get_object_or_404 
from .forms import EmailPostForm, CommentForm, SearchForm 
from taggit.models import Tag 
from django.db.models import Count 
from django.contrib.postgres.search import SearchVector 


def post_list(request, tag_slug=None): 
    posts = Post.published.all() 
    tag = None 
 # 如果请求中有tag_slug，则获取标签并按标签过滤文章数据 
    if tag_slug: 
 # 获取标签 
      tag = get_object_or_404(Tag, slug=tag_slug) 
 # 按标签过滤文章 
      posts = posts.filter(tags=tag)

    paginator = Paginator(posts, 3)
    page = request.GET.get('page')

    try:
        posts = paginator.page(page) 
    except PageNotAnInteger: 
        posts = paginator.page(1) 
    except EmptyPage: 
        posts = paginator.page(paginator.num_pages) 
  
    return render(request, 'blog/post/list.html', {'posts': posts, 'page': page,'tag': tag})

def post_detail(request, year, month, day, post): 
 post = get_object_or_404(Post, slug=post, status='published', 
    publish__year=year, 
    publish__month=month, 
    publish__day=day) 
 comments = post.comments.filter(active=True) 
 new_comment = None
 # 找到所有相似文章
# 找到当前文章的标签编号 
 post_tags_ids = post.tags.values_list('id', flat=True) 
# 找到包含当前文章任意标签的文章集合（除当前文章外） 
 similar_posts = Post.published.filter(tags__in=post_tags_ids)\
   .exclude(id=post.id) 
# 对相似文章按照相同标签数量进行排序，取前4个，相同标签数量使用聚合函数Count
# 计算后保存在same_tags中，以便后续使用 
 similar_posts = similar_posts.annotate(same_tags=Count('tags'))\
   .order_by('-same_tags','-publish')[:4]

 if request.method == 'POST': 
 # 获取请求中的评论数据构建评论表单 
    comment_form = CommentForm(data=request.POST) 
 # 如果通过表单有效性校验则构建评论数据并保存 
    if comment_form.is_valid(): 
        new_comment = comment_form.save(commit=False) 
        new_comment.post = post 
        new_comment.save() 
 else:
    comment_form = CommentForm()
 return render(request, 
    'blog/post/detail.html', 
     {'post': post, 
     'comments': comments, 
    'new_comment': new_comment, 
    'comment_form': comment_form,
    'similar_posts': similar_posts})

# 上方无变化代码已经省略
def post_share(request, post_id): 
 post = get_object_or_404(Post, id=post_id, status='published') 
 # 设置发送状态为未发送 
 sent = False 
 # 如果请求是POST表示有提交表单 
 if request.method == 'POST': 
 # 通过EmailPostForm表单类获取请求中的表单数据后保存到form中 
    form = EmailPostForm(request.POST) 
 # 如果表单数据验证通过则发送邮件并将状态设置为已发送 
    if form.is_valid(): 
        # 获取表单中的数据 
        cd = form.cleaned_data 
 # 构建请求路径 
        post_url = request.build_absolute_uri(post.get_absolute_url()) 
 # 构建邮件标题 
        subject = f"{cd['name']} recommends you read " \
              f"{post.title}" 
 # 构建邮件正文 
        message = f"Read {post.title} at {post_url}\n\n" \
        f"{cd['name']}\'s comments: {cd['comments']}" 
 # 发送邮件 
        send_mail(subject, message, '1279515362@qq.com', 
                  [cd['to']]) 
 
 # 发送状态设置为真 
        sent = True 
 else: 
 # 如果表单数据验证未通过将表单设置为空 
    form = EmailPostForm() 
 # 渲染分享文章模板，并将文章、表单、发送状态信息传递给文章分享模板 
 return render(request, 'blog/post/share.html', {'post': post, 
                                                 'form': form, 
                                                'sent': sent})

def post_search(request): 
 form = SearchForm() 
 query = None 
 results = [] 
 
 # 如果请求中有query字段则获取表单中的数据进行处理 
 if 'query' in request.GET: 
 # 获取表单 
   form = SearchForm(request.GET) 
 # 如果表单中的数据验证通过，即有效，则获取并处理 
 if form.is_valid(): 
 # 获取搜索内容保存下来 
      query = form.cleaned_data['query'] 
 # 根据标题和正文字段构建搜索向量并生成搜索字段，再根据搜索内容筛选出匹配内容保存 
 results = Post.published.annotate( 
   search=SearchVector('title', 'body') 
 ).filter(search=query) 
 # 将搜索结果渲染到搜索模板并返回 
 return render(request, 
   'blog/post/search.html', { 
   'form': form, 
   'query': query, 
   'results': results 
 })


